Bug#761869: debsources: "update statistics" stage is too slow
Package: qa.debian.org
Severity: normal
User: qa.debian.org@packages.debian.org
Usertags: debsources
The "update statistics" stage of Debsources updated is currently too slow,
taking ~12 minutes on the current sources.d.n machine.
It could be easily optimized by avoiding redoing queries for each live suites
(currently: 9), where each query will do a sequential scan (due to count(*),
despite "index mostly scan") over the same data. Instead, we can use GROUP BY
queries, taking at once stats for all suites.
(See proof of concept and benchmarks available in
doc/update-stats-query.bench.sql)
-- System Information:
Debian Release: jessie/sid
APT prefers testing
APT policy: (500, 'testing'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 3.14-2-amd64 (SMP w/4 CPU cores)
Locale: LANG=it_IT.UTF-8, LC_CTYPE=it_IT.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
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